Given that,
The decend rate = r = 95 feet in 5 seconds.
We can write this like that,
In 5 seconds, a parachutist descends = 95 feet
In 1 second, a parachutist descends = 95/5 feet
=> 19.
Hence, the rate of the parachutists change in height as a unit rate is 19 feet per second.